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Never a carb problem until now...

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This past winter I put my bike away running well and winterized it. I decided to put in a new Wiseco Piston, rings, and new cylinder. I also decided to go from a K&N air filter to a Unifilter for better air cleaning. I get the bike all back together this past weekend and it will not start. There is spark, plug is new, gas flow, valves are within spec (10 hours on new Kibblewhite valve train and hot cams)....BUT....there is constant drip from the fuel over flow tube. So, I take the bike's carb apart clean the pilot and jet and make sure the float is not sticking. I put it back together and try starting the bike again...starts for like 2 seconds and dies without me touching anything...all while the fuel over flow tube is constantly dripping out fuel. I look at my plug and its saturated with fuel and you can smell the fuel from the pipe exit. I'm just trying to figure out if the float is set so high that it is flooding my bike before I can even start it?!?!? I've never had a carb problem with this bike, but I guess sitting there something happened? lol

I have a 2004 RMZ 250

Main Jet is 180

Pilot is 42

The air/fuel screw is out 2 turns

Needle is set at 3rd notch down

Temperature is 32 degrees (still winter) and 600-800 feet above sea level.

I have full Yoshimura exhaust with Unifilter in the air box.

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yeah, it's the float... could be a seat thing. Test it with the bowl off. Then you'll know for sure. -BIG DAN:thumbsup:

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yeah, it's the float... could be a seat thing. Test it with the bowl off. Then you'll know for sure. -BIG DAN:thumbsup:

What am I looking for when the bowl is off? I can rebuild a whole bike, but the carburetor is my enemy. lol

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Make sure the float level is set right 1st. If it is set right then check the float needle. The float is connected to a needle, so that when the float bowl fills with gas and raises the float, it presses the needle into an orfice (small hole) and stops gas from entering the carb from the gas tank. If you pull the needle out and look at it, it will probably have a ring around it from normal wear. Replace that little needle and your woes will be gone. :thumbsup:

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:thumbsup:Well said my friend.:thumbsup:

Also. If you want to test any motorcycle carburetor, with the float bowl off, fuel line hooked up, and a catch bucket below.

1. Turn on the petcock and fuel should flow readily. All over the ground hopefully you'll catch 25% in the bucket to put the Enviros at ease.

2. Push up gently on the floats and the fuel will slow or stop all together. Stop is what should happen but in your case, It might not stop all the flow.

If it doesn't stop flow completely your needle is bad. Sometimes the seat it seals to can be the problem.

If it stops flow completely, see at what level it works. Should be near level. If this is all good. Re-assemble carb and bike and Try again.

If still pouring out overflow, re-adjust the float needle tang with a little screwdriver (gently now) so that it closes sooner. You'll get the picture when you're doing it. Good luck. -BIG DAN:thumbsup:

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Thanks a lot guys! I'm down at school right now and will head home to figure this mess out. When I bought this bike last August I did replace the float needle. Hopefully the level is just off for some reason? I did wipe out pretty good the last time I went out riding in December and then winterized the bike and put it away until last weekend. Maybe the spill did something? Either way I'll do all this tomorrow! Thanks again!

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there's also an o-ring around the seat, may want to pull it and check or replace it also. if it's worn, fuel will leak around the needle and seat assy, and into the bowl.

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